


When the World Ended.

by Kaiyomatsu



Series: Inktober Challenge [1]
Category: Fallout 4, おそ松さん | Osomatsu-san (Anime)
Genre: Action/Adventure, Alternate Universe - Post-War, Blood and Violence, Disasters, Family Bonding, Fluff and Angst, Gen, Good Brother Osomatsu, Nuclear Weapons
Language: English
Status: Completed
Published: 2020-10-01
Updated: 2020-10-01
Packaged: 2021-03-07 21:53:51
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 2,569
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26744689
Author URL: https://archiveofourown.org/users/Kaiyomatsu/pseuds/Kaiyomatsu
Summary: It happened. It finally happened. And just when life for six identical NEETs couldn't get any shitter, the unthinkable happened.
Relationships: Matsuno Choromatsu & Matsuno Osomatsu
Series: Inktober Challenge [1]
Series URL: https://archiveofourown.org/series/1946911
Kudos: 15





	When the World Ended.

**Author's Note:**

> First Story for Inktober. :)

_**"Day...15 outside of the vault. So far we've encountered twenty super mutants, damn near thirty Ghouls, fifteen Mirelurks, um twenty-six mole rats, and I'm pretty sure Osomatsu-niisan is addicted to chems.--"** _

_**"Like hell I am! Get off that fucking recorder, we've gotta go!"**_ Osomatsu snapped irritably after blowing the head off a raider with his combat shotgun.

Choromatsu's face turned pale at the sight. **_"Jesus Fucking Christ, what the hell is wrong with you!?"_**

The eldest furrowed his eyebrows as he frowned, _**"What are you talking about I'm fine!"**_

The 3rd born quickly turned off his recorder and turned to Osomatsu angrily. "No, you're fucking not! You just...you just...!"

"Saved your life? You're welcome by the way," he replied resting his gun on his shoulder. "He was about to stab you, what did you expect for me to do? Just stand here and let that happen?"

Choromatsu looked down at the remains, he saw the man with the war paint all over his face indeed gripping a knife as his headless corpse lay still in the brown scratchy grass. "I..." he then glanced at his brother who for the most part seemed completely fine. "You...you don't feel bad...about any of this?" he asked softly.

"Why would I?" Osomatsu said simply staring at Choromatsu more confused than angry, he then glanced around listening. "We should get out of here, dunno what else can pop up ya know?"

Choromatsu's gaze traveled back down to the corpse, he opened his mouth to say something in retort but quickly closed it and nodded to Osomatsu's actually wise suggestion. 

Once the eldest holstered his weapon on his back, he casually took Choromatsu's hand and pulled him along back to their hide-out which was about a mile's walk from where they were in the devastated remains of Akatsuka ward. Thanks to Hatabou and his piles of money and love for his friends he was able to gather most of them into his secret bunker to which the opening was under the Flag corporation building which turned out to be a tunnel down into his secret hideaway.

Everyone, for a while, seemed relieved to know that they had escaped the annihilation of their way of life, to Osomatsu it seemed pretty cool that he no longer had to worry about working anymore- which earned him a slap from Totoko who wailed over the idea of being unable to go outside and worse being stuck with the six of them (mainly Osomatsu) for damn near 200 years. Nyaa-chan worried about her fans, Matsuyo wondered about her chances of getting a grandchild now since her boys WERE literally sealed in a bunker with not one, not two, and not three and not four but FIVE girls who the boys knew at one point in time or another.

She liked her odds but their father Matsuzo was more of a realist knowing these girls would rather die of radiation poisoning than think of repopulating with their good for nothing sons.

Dekapan on the other hand had the perfect reaction of screaming and freaking out with Dayon over the fact that the world had literally ended and they were all stuck underground for the rest of their lives.

Iyami freaked out as well namely because (just like Totoko) because he was stuck in a vault with the six demons of Akatsuka- Ward. The Matsuno Sextuplets. 

Seemed to be the main theme of fear with only a few not worrying about it, and that was Nozomi who was more anxious about her parents who didn't make it- she hoped they'd at least find some kind of shelter similar to the one she was in.

Of all the days to visit Akatsuka ward only to have it nuked.

As for Homura well...Jyushimatsu ran out WHEN the bombs fell- grabbed Homura and brought her back to the vault before the impact.

How he did such a feat the world will never know, with his precious Homura safe and sound, his brothers, his parents, and his baseball bat, it was a good day despite everything.

Ichimatsu seemed to pick up on Jyushimatsu thinking this to himself quite often.

Speaking of which, Ichimatsu, once dragged into the Vault; was more quiet than normal. In fact, he was _eerily_ too quiet. With a few kittens, he was able to snatch before the bombs fell- he had been staring at them and feeding them round the clock whenever they seemed hungry. No one dared but Jyushimatsu to ask how he was doing and he got the answer quite easily.

_**Horribly.** _

He was doing _**So. So. Horribly.**_

All those cats who were his friends. All of them. Cat Island itself.

It was all gone. In his mind, these were probably the only cats left in Japan, the responsibility felt like a noose tightening around his neck. Once this was relayed to the rest of his family, of course, the others did their best to keep Ichimatsu from thinking too deeply into that scenario. This might or might not be true, but considering there are PLENTY of cats in Japan, maybe more got into other bunkers and will make more kittens to keep the population going.

The Matsuno family of course stuck to the positive outcome in regards to Ichimatsu with that subject matter.

"We're BAAAACK!" Osomatsu called jumping back into the vault with Choromatsu in tow- struggling with all the loot the eldest had dumped on him. "Did ya miss me?" he said chuckling as he rubbed under his nose with his finger.

Dekapan was the one standing by the entrance wearing a lab-coat holding a battered clipboard. "Welcome back dasu, how was your trip to the surface you two?"

"It was fine." 

"Not the word I'd use," Choromatsu replied tossing the bag onto the table for Dayon- dressed in a policeman's outfit, to examine and inspect for later weapons, chems, or experiments. 

"Hoi?" Dekapan tilted his head to the side curiously as Osomatsu rolled his eyes at Choromatsu's response. "What happened out there?"

Scratching the back of his head Osomatsu was ABOUT to answer but was beaten to it by his 3rd youngest twin. "He killed someone," Choromatsu said sternly crossing his arms and glaring at him.

"Okay, that's bullshit." 

"Is it?"

"Yes! I SAVED you!" The eldest shouted, exasperated.

Dekapan glanced at Choromatsu sympathetically. "I understand how you feel dasu but we are in a different world from the one we were in. Your brother was only-"

"You didn't see what I saw!" Choromatsu interrupted, arms still crossed. "It was...it was..."

"Messy?" Osomatsu finished. "Yeah that's...kinda what happens when I shoot someone that close in the face with this bad boy," he said gesturing proudly to his shotgun that he himself customized. All it earned him was a wince from Dekapan and an incredulous look of shock from Choromatsu.

" _You've done this before!?!?_ " he screeched, making it Osomatsu's turn to wince at how high pitched the 3rd born could go.

"Done what!?" Osomatsu snapped back putting his hands down at his sides. "Protect myself? Make sure I got back home in one piece!? Actually, make myself useful?"

"Killing people isn't making you useful- it makes you psychotic! That and those chems!"

The accused crossed his arms and rolled his eyes leaning against the frame to the large door of the vault. "Oh give me a break..." he groaned, "I use Jet and Med-X and a little bit of buffout. What's the big deal? The others use it too!"

"Because YOU use it!" Choromatsu yelled with a stomp of his foot. "That stuff shouldn't even BE in here and yet here you are using it like it's nothing!"

"Well it's not nothing, it keeps me alive thank you very much." Osomatsu said with a nonchalant shrug which pissed Choromatsu off even more.

"It's destroying you!"

"Oh well."

"So you don't care it's doing the same to Karamatsu and the others huh?"

He narrowed his eyes at Choromatsu. "I didn't say that, don't put words in my mouth!" At this point, Dekapan found it paramount to step in and control the situation.

"G-Gentlemen! Gentlemen!" he said loud enough to garner both of their attention. "Please dasu, you're both just very stressed and tired from the journey, w-why don't you go on down and see what's to eat dasu? I heard your mom is making good use of all the meat the others had brought in yesterday."

Osomatsu sighed "Whatever." he then continued down the hall to the elevator, Choromatsu quietly gave his thanks to Dekapan and Dayon to which they thanked him in return for even going.

They certainly weren't going to take the chance!

* * *

Silently the firstborn and the thirdborn Matsuno stood together in the cramped and dingy elevator, neither of them sparing a glance to the other as they quietly seethed over their earlier disagreement. 

Osomatsu opened his mouth to speak but before he could even get a word out Choromatsu raised his hand to him- still not looking in his general direction.

"For me. Could you at least ease up on the chems...? A little bit?"

"You're not...mad at me anymore?"

Choromatsu finally glanced at the eldest and shook his head. "I'm worried you jackass. I don't want you acting like some mindless raider okay? Call me crazy but YOU being crazy usually doesn't spell out good news for us."

Osomatsu smirked. "When have I ever been sane? I mean really?"

"Good question- but that's beside the point! The point is you're going out there and taking drugs and killing people left and right--"

"I am _Not_ just going out there getting high on drugs and killing people. Sure I've gotten sloshed at certain bars with some normal ghouls, maaaaayyyybe slept around here and there- but overall I've been on my best behavior!" he said with a smile giving his twinie a thumbs up and a wink.

This only resulted in the 3rd born sighing as he rested his hand against his aching head. "I can still hear that fucking gun of yours."

"Sorry...I didn't mean for you to be so close." 

"And that sound of...his head...just..."

Osomatsu quickly grabbed Choromatsu's shoulders before he could finish his sentence, identical brown eyes staring at each other. "I'm not sorry," Osomatsu stated firmly.

"Wha--?"

"That asshole was gonna slit your damn throat, and I'm not sorry I killed him. After everything that's happened, you think I'm going to let some guy tear any of you away from me? I'll take as many chems as I need and kill as many people as I have to if it means you guys stay by my side." he smiled tiredly. "It's not fun...heh...I get one hell of a stomach ache and my vision gets all blurry when I take too much."

"S-So you do...overdo it..." Choromatsu's voice was much different now, less annoyed or pissed off, but heartbroken. "I knew it, see I told you--!!"

"Like I said I'm not apologizing for it, because I know why I'm doing it. Relax, I won't go TOO deep into it and end up killing myself." he chuckled.

"That's not funny."

"You're right it's not," Osomatsu said, he then smirked, which earned him a slap over the head. 

"Dumbass! How in the hell would you know what's too much?! If you O.D there's no way for us to save you- no guaranteed way out there for sure! Imagine one of us trying to drag your stupid body back to the vault for Dekapan to--!"

Osomatsu simply chuckled resting his forehead against Choromatsu's who continued to fret and fuss at the firstborn.

"It's not funny damn it!" 

He nodded. "It's not funny." While desperately trying to hold in his chuckles. "It's not funny."  
  
Choromatsu was seriously getting pissed off- and wondering what was taking this elevator so long to get down to the bottom where the others were. "You're laughing! So obviously you must think this is all some big joke!!"

"Heheh nope, you're wrong on that too." he said lifting his head up to smile at the third born.

" _Then WHAT is so fucking hilarious!?_ "

"My luck," Osomatsu said simply, making Choromatsu beyond confused.   
  
"What?"

"My parents are alive with me, my friends, even one we haven't seen in a long time. Right now I'm arguing in an elevator with you as we go down to see the rest of our family." Osomatsu began to laugh even as tears began to gather at the corner of his eyes. "I just- I just realized it you know? How some other families are probably doing now, I-I mean we...Dekapan froze us for about 300 years and we've seen s-so many families ripped to shreds by either Mutants, Raiders, Gunners, or some other fucked up and horrible thing this place has to offer and yet...heh...and yet I still have you guys."

It dawned on Choromatsu that Osomatsu's laughs were slowly delving into tears, glancing at the elevator panel he slowly reached out and pressed the stop button before wrapping his arms around the eldest letting him continue.

"I-I mean sure, our house is gone, we've gotta really work to survive here but...you guys are still here...y-you're still my brothers..."

Choromatsu softly scoffed patting his back. "Of course we're still your brothers you idiot..." he said this in an endearing way of course. "Not even a nuclear holocaust is gonna change that I'm afraid."

"Heheh, good." Osomatsu happily hid his face in Choromatsu's dirty green hoodie, hands still holding onto his shoulders firmly as if Choro was gonna disappear right then and there. "That's why...I...I gotta do what I gotta do...so..."

"Yeah..." Choromatsu looked away, his face reddening to the tips of his ears. "Makes sense."

The other looked up at him grinning, despite the tears still lingering in his eyes. "You mean it?"

"I mean...don't get the wrong idea, I still think it's fucked up you're so...calm about the whole...killing people and taking drugs but..." he sighed. "I understand. You're actually...really stressed about this whole mess just as much as the rest of us are." he inhaled audibly closing his eyes to gather all his thoughts into a simple sentence. Choromatsu then exhaled and said. "Don't be a fucking moron and overdo it okay?"

Osomatsu saluted eagerly. "Haaaaai~!" 

Choromatsu gently moved the other off of him and pressed the button on the elevator bringing it back online to continue it's descent down. "Can't have you dying on me either," he mumbled.

"What was that?"

Once again Choromatsu's face went as red as Osomatsu's hoodie, he sputtered keeping his back to the eldest. "I-I said just don't go off dying period! We'll never hear the end of it from mom and dad!!"

Osomatsu pouted. "So mean~ And after Niisan's heartfelt speech too?" he smirked, "Fine fine, I'll try not to get myself blown up or something! Hahaha!"

Choro groaned rolling his eyes before rubbing his heated cheeks trying to rub the redness and stray tears away. "S-so stupid..." Suddenly he felt two arms around his shoulders and a sudden kiss on his cheek. "E-Eh!?"

"I love you too, Chorofappyski~"

" _ **Ghk!!!**_ "

* * *

From outside the elevator, everyone else could clearly hear Choromatsu scream-

_**"STOP CALLING ME THAT!!!"**_

Along with Osomatsu amused laughter.

**Author's Note:**

> More stories to come, if you guys have any ideas on what I should write for the next 30 days next lemme know in the comments. :)


End file.
